Wheel-electrode assemblage for honeycomb core welding system



Jan. 4, 1966 F. H. ROHR ETAL 3,227,850

WHEEL-ELECTRODE ASSEMBLAGE FOR HONEYCOMB CORE WELDING SYSTEM OriginalFiled June 29, 1962 8 Sheets-Sheet 1 FIG.

INVENTORS- F. H. ROHR BY E. M. LACEY A TTORNEY Jan. 4, 1966 F. H. ROHRETAL 3,227,850

WHEEL-ELECTRODE ASSEMBLAGE FOR HONEYCOMB CORE WELDING SYSTEM 8Sheets-Sheet 3 Original Filed June 29, 1962 NVN mmw

mmw

ATTORNEY Jan. 4, 1966 F. H. ROHR ETAL 3,227,850 WHEEL-ELECTRODEASSEMBLAGE FOR HONEYCOMB CORE WELDING SYSTEM Original Filed June 29,1962 8 Sheets-Sheet 4 INVENTORS.

F. H. ROHR E. M. LACEY 0 a a 3'; t)

AT ORNEY Jan. 4, 1966 F. H. ROHR ETAL WHEEL-ELECTRODE ASSEMBLAGE FORHONEYCOMB CORE WELDING SYSTEM 8 Sheets-Sheet 5 Original Filed June 29,1962 FIG. 7

INVENTORS.

F H. ROHF? BY E. M. LACEY AT ORNEY Jan. 4, 1966 F. H. ROHR ETAL3,227,850 WHEELELECTRODE ASSEMBLAGE FOR HONEYCOMB CORE WELDING SYSTEMOriginal Filed June 29, 1962 8 Sheets-Sheet 6 I ll MS @OHI Fl 6. G.INVENTORS.

F. H. ROHR BY E. M. LACEY I ATTORNEY Jan. 4, 1966 F. H. ROHR ETAL3,227,850

WHEEL-ELECTRODE ASSEMBLAGE FOR HONEYCOMB GORE WELDING SYSTEM OriginalFiled June 29, 1962 8 Sheets-Sheet 7 INVENTORS.

F. H ROHR 37 F16, [8 y E. M. LACY ATORNEY Jan. 4, 1966 ROI-IR ETALWHEEL-ELECTRODE ASSEMBLAGE FOR EONEYCOMB CORE WELDING SYSTEM 8Sheets-Sheet 8 Original Filed June 29, 1962 INVENTORS.

F H. ROHR BY E. M. LA CEY ME ATTORNEY United States Patent 3,227,850WHEEL-ELECTRODE ASSEMBLAGE FOR HONEY- COMB CORE WELDENG SYSTEM Fred H.Rohr, San Diego, and Elbert M. Lacey, Chula Vista, Califi, assignors toRuhr Corporation, Chula Vista, Califi, a corporation of CaliforniaOriginal application June 29, 1962, Ser. No. 207,163, now Patent No.3,190,999, dated June 22, 1965. Divided and this application Mar. 12,1965, Ser. No. 452,958 5 Claims. (Cl. 21984) The invention relatesgenerally to apparatus for fabricating honeycomb core and moreparticularly to a wheelelectrode assemblage for a welding system havingparticular utility when used with the honeycomb core fabricatingapparatus disclosed in the copending application for Novel Framework forHoneycomb Core Machine, Serial Number 103,589, filed April 17, 1961.

This application is a division of our copending application for WeldingSystem for Honeycomb Core, Serial No. 207,163, filed June 29, 1962. Thisapplication is now Patent No. 3,190,999.

Although not limited thereto, the welding system of the presentapplication and the apparatus disclosed therewith in the aforesaidcopending application are particularly well suited for use in providingthe basic welding pin, wheel, and core shuttling movements disclosed andclaimed in the copending application of Fred H. Rohr for Method andApparatus for Fabricating Honeycomb Core, Serial Number 846,903, filedOctober 16, 1959.

Many manufacturing processessuch as weldingre quire that several partsbe brought together and assembled precisely at the work station; held atthe work station in such assembled relation for the duration of thewelding period; and then shuttled out of the work area to make way forsuccessive parts to be introduced, assembled, and acted upon within thework station. A situation of this type arises in the fabrication ofso-called honeycomb core that is widely used in airplanes forlow-weight, highstrength structure. In the fabrication of this honeycombcore, strip feed and corrugation means operate in timed relationcooperatively with internesting electrode and indexing pins which serveto move sections of corrugated metal ribbon or strips into juxtaposedalignment so that the troughs of one strip rest on the crests of anotherstrip preparatory to the welding of the same together. The strips arethen held in this position while coacting electrode pins and weldingwheels pass the welding current through the abutting and juxtaposednodes of the adjacent crests and troughs to thus weld the same togetherand form cells of the honeycomb core. When selected crests and troughshave been welded together, the electrode pins and welding members arewithdrawn from the thusly formed cells and, following the shuttling ofthe core by the indexing pins, re-inserted and re-applied as the processis repeated, as necessary, to complete the core.

For a completely satisfactory result, providing high quality honeycombcore, the corrugating and juxtapositioning of the strip actions must bevery precise, the abutting nodes to be welded must be criticallypositioned above the electrode pins, and the welding wheels must becaused to track precisely above and along the electrode pins in orderproperly to pass the welding current therebetween and through theabutting nodes, all in a manner to form optimum welds in the nodal areaswhile avoiding burning of the thin stainless steel ribbon material atthe sides of the nodes. To this end, the pressure, movement, andelectrical contacting of the welding members, particularly theelectrical circuit continuity through the welding wheels must becritically controlled; and the precision positioning, alignment, andrelative movement of parts must persist repetitively in the cell-to-cellformation throughout the length and width of the core. It followstherefore, that the welding members per se must be adapted to maintainstructural integrity and fixed operative relationships as well aselectrical circuit continuity during the welding process and, to thisend, the framework structures and surfaces that support and guide thepositioning and welding members must be strong, sturdy, and carefullyaligned. These framework and supporting structures, moreover, like thewelding members per se, must be capable of retaining their relationshipduring the welding process and, in addition, repetitively retain suchstructural integrity and relationship of the parts during the shuttlingand other movements preparatory to welding of successive sections of theribbon material.

Various honeycomb core fabricating machines employing internestingelectrode fingers and coacting welding wheels have heretofor beendevised and used with varying degrees of success. In the past, forexample, the electrode pins have been clamped in mutually spaced andparallel relationship to a common support bar which also served as aconductor in the electrical welding circuit, the arrangement being suchthat current would enter one wheel and pass through a first pair ofabutting nodes to a first electrode pin and then pass through thesupport bar to the second electrode pin from whence the current wouldpass through a second pair of abutting nodes to a second wheel at theother end of the welding circuit. Although this arrangement has theimportant advantage of simplicity in that terminals are required onlyfor the pair of wheels in the series circuit, the electrode pins beingintermediate elements in this circuit, the series circuit arrangementhas the disadvantage in that inordinately high resistance or low contactpressure of one wheel and electrode pin in the series circuit affectsthe welding current available to the other wheel and electrode pin ofthe series circuit. In the clamping of the electrode pins to the commonsupport bar, moreover, electrical difliculties are encountered due tovariations in the clamping resistance of the several pins, andmechanical difficulties arise in achieving precise positioning andspacing of the clamped plnS.

Among the several objects, features and advantages of the welding systemof the present invention is the provision of an arrangement wherein eachwheel and coacting electrode are separately energized from the currentsource, and each sub-assembly of the wheel and its mount, and thecontact pressure control which is made individual to each wheel andsubassembly, are made individually adjustable, mountable, andreplaceable as a unit sub-assembly, or modulator component, in the eventof malfunctioning and need for replacement and repair.

As another object, feature and advantage of the present invention,provision is made for interchange of wheel sub-assemblies of differentsizes in accordance with differences in cell sizes of core to befabricated, and provision is further made for the precise shifting ofthe wheels when it is desired to weld alternate nodes in a forward sweepof the welding wheels across the core and to weld the intervening nodeson the return sweep of the welding wheels across the core. This movementis combined, moreover, with the required lowering and raising movementof the wheels as necessary to move them into and out of contact with theabutting ribbon nodes to be welded. This mounting means or welding head,and the movements effected thereby, assure alignment of the wheels withthe electrode pins, notwithstanding the fact that the same wheels may berequired to align with different electrode pins, as where the wheels areshifted to weld alternately spaced nodes, as aforedescribed.

As another object, feature and advantage of the present invention, theelectrode pins and the indexing or shut tling pins of each group areprecisely positioned and mutually spaced, as with the aid of jigs anddies, and then potted with a suitable plastic, each group in its holder,to thereby assure that the pins in their movements into and out of thecells of the core during fabrication of the same will retain the samespacing and will encounter the same freedom of entry and withdrawalwithout resulting premature wearing of the pins or impairment to thestructural integrity of the core and its ribbon material, The electrodepins, being formed of highly conductive copper, are naturally subject towear in engagement with the harder stainless steel material of which thecore is fabricated and, accordingly, the tapered tips of the pins arecoated with a hard plating such as chromium. The electrode and indexingpins are similarly molded in their respective holders with the moldedplastic serving, as aforementioned, to precisely spaced and position thepins in each case, while also affording essential electrical insulationfor the electrode pins. The electrode and indexing pin assemblies asthus provided, like the welding wheel sub-assemblies, are modularcomponents which readily may be replaced in the event of malfunctioningand need for replacement and repair, it thus being possible to rapidlydetermine critical areas of malfunctioning of the machine, make theneeded repairs and replacements, and expeditiously return the machine toproduction operation.

Still another object, feature and advantage of the welding system of thepresent invention which contributes to the precise tracking of thewheels along the nodes as well as to the quality and uniformity of thewelds per se, resides in the provision of novel rotative support for thewelding wheels wherein three critical and essential functions areafforded thereby, namely, true and rotative movement about the bearingaxis, an absence of wobble from side to side on the bearing axis, andcircuit continuity and conductivity compatible with the other circuitelements of the welding circuit.

Yet another object, feature and advantage of the welding system of thepresent invention is the provision for precise shuttling movement of theindexing pins whereby the core is moved thereby accurately in multipleincrements of the spacings between adjacent nodes to thus assure thatcells of the core into which the electrode fingers are to be insertedwill always be aligned axially with the pins, and this beingaccomplished, notwithstanding the requirement of the indexing pins toshuttle the core in both directions longitudinally of the ribbons of thecore.

Still another object, feature and advantages of the welding system ofthe present invention resides in the particular shaping, in crosssection, of the electrode and indexing pins wherein the same are made toaccommodate extruding portions of the cell walls of the corrugatedribbon resulting from the piercing of the same to provide gas escapeopenings in the cell walls of the fabricated core. Thus, although theprotrusions of the perforations alternately face upwardly and downwardlyas the continuous ribbon is folded back and forth upon itself, the pinsare shaped in cross section such that the protrusions do not impair theotherwise free entry and withdrawal of the pins from the cells of thecore.

An additional object, feature and advantage of the present invention isthe provision of an air jet hold down which serves to urge the ribbonagainst the pins preparatory to and during welding of the same to thecore, and also serves to cool the welding wheels during the weldingprocess.

A principal object of the present invention therefore is to provide anew and improved welding system for fabbricating honeycomb core havingprovision for precise tracking of the wheeels across the aligned nodesof the ribbons to be welded together having provision for parallelrelative movement of the wheels and pins parallel to the axes of theelectrode and indexing pins, having provision for precise indexingmovements of the wheels, pins and 4 core relative to each other, andhaving provision for assuring circuit continuity and optimumconductivity for the purpose as well as optimum contact pressure of thewelding wheels, while also having provision for ready assembly andreplacement of parts.

Still other objects, features and advantages of the present inventionare those inherent in the novel construction, combination andarrangement of parts comprising the welding system, presently to bedescribed, which has been constructed in accordance with the best modethus far devised for practicing the principles of the invention,reference being had to the accompanying drawings wherein:

FIG. 1 is a fragmentary view, somewhat enlarged, of a honeycomb core inthe process of being welded;

FIG. 2 is an isometric view of a framework which, taken with thecomponents of the welding system, embodies the basic inventive conceptof the present invention;

FIG. 3 is a plan view of the machine shown in FIG. 2, certain partsbeing removed;

FIG. 4 is a View in section of the machine taken along the line 4-4 ofFIG. 3;

FIG. 5 is a fragmentary front view of the machine;

FIG. 6 is an enlarged fragmentary sectional view as seen along the line6-6 of FIG. 5;

FIG. 7 is a plan view of the electrode pin assembly;

FIG. 8 is a sectional view of the electrode pin assembly as seen alongthe line 83 of FIG. 7;

FIG. 9 is a sectional view of the indexing pin assembly, this view beingsimilar to that of FIG. 8;

FIG. 10 is a sectional view of an indexing pin as seen along the line1010 of FIG. 9;

FIG. 11 is an enlarged side elevation of the wheel assembly disclosed inFIG. 4, certain parts being broken away to disclose features ofconstruction and arrangement of parts;

FIG. 12 is a front view of the wheel assembly disclosed in FIG. 11;

FIGS. 13 and 14 are top fragmentary views of wheel assemblies showingalternative wheel spacing arrangements;

FIG. 15 is a side elevation of a wheel sub-assembly;

FIG. 16 is a sectional view of the wheel sub-assembly as viewed alongthe line 1616 of FIG. 15;

FIG. 17 is a sectional view of the wheel sub-assembly as viewed alongthe line I7-ll7 of FIG. 15;

FIG. 18 is a fragmentary exploded vie-w of the wheel sub-assembly ofFIG. 15; and

FIG. 19 is an exploded view of the mount for the wheel sub-assemblies.

Referring now to the drawings for a more complete understanding of theinvention, and first more particularly to FIGS. 2 to 4, there is shownthereon a honeycomb core fabricating machine which is functionallyequivalent to that disclosed and claimed in the aforesaid copendingapplication of Fred H. Rohr, Serial Number 846,903, that is to say, bothmachines have the same basic components and the same basic movements.Thus, both machines comprise a welding wheel assembly or Welding headgenerally designated 13, an electrode pin assembly 11, an indexing pinassembly 12', and a supporting framework generally designated 13.

A core in the process of fabrication on the machine is generallydesignated 14 and is built up from an endless corrugated ribbon 15 whichis supplied from a source (not shown) such as the strip feed andcorrugating apparatus disclosed and claimed in the copending applicationof Elbert M. Lacey, Jr., for Method and Apparatus for Feeding MetalStrips, Serial Number 78,720, filed December 27, 1960. The ribbon sosupplied is received by way of a suitable chute or slide 9 and a wineglass shaped feed control device 16 which forms a hopper in its upperportion into which the ribbon 15 may fall into one or more loops such asindicated at 17. Feed control de vice 16 also has a narrowed throatportion 18 providing.

a restricted opening which approximates the thickness of the corrugatedribbon, that is to say, the dimension corresponding to the depth of atrough or the height of a crest, as the case may be. The restrictedopening serves to keep the ribbon supplied to the core under sufiicienttension, short of stretching and deforming the same, such that theribbon nodes fall naturally into alignment with the confronting nodes ofthe previously formed core layer. On leaving the throat 18, the ribbonis fed and guided outwardly of the device 16 through the open bottomthereof in either direction longitudinally of the core and into whatdecomes the upper layer of the core as the same is shuttled in eitherdirection to the right or to the left of the machine.

The electrode pins 19 move axially into and out of what constitutes theupper row of completed cells of the core 14, and the indexing pins 21move axially into or out of what constitutes those cells which are beingnewly added to the core upon welding of the ribbon 15 thereto.

Electrode pins 19 which in the specific case, as shown, may be 12 innumber, are precisely formed and precisely mounted and spaced in aheader member 20 to which they are suitably secured as by being pottedin a body of suitable plastic such as an epoxy resin molded within themember 21%. When so formed, the electrode fingers or pins '19 closelyfit the cell configuration, as may be seen in FIG, 1, but may be freelymoved axially thereof into or out of the cells of the core 14. Indexingpins 21 are similarly formed and precisely spaced and mounted in aheader member 22 comprising the indexing pin assembly 12.

Electrode pins 19 lie generally within the plane of the cells of thecore 14 formed by the previous welding thereto of a length of ribbon 15extending along the length of the core. The indexing pins 21 aredisposed in internesting relationship with the electrode pins 19 and aredisposed generally in a plane spaced one-half cell width above the planecommon to the electrode pins. As otherwise expressed, the indexing pinsare disposed generally in a plane of those cells which are being newlyadded to the core to form the upper layer of cells thereof.

Both the electrode and indexing pins are mounted for movement axiallythereof into and out of the cells of the core, and the electrode pinswhen so inserted into the core, are in supporting relation with respectthereto, the core being depended from these pins and supported, at leastin part, therefrom. The indexing pins 21, on the other hand, wheninserted into position on the core, are disposed beneath a section ofthe corrugated ribbon 15 which is to be welded to the core and,consequently, do not initially provide a support function for the core.When the welding of this ribbon section has been com pleted and the sameis secured to the core, and when the electrode pins have been withdrawnaxially from the core, the core is then supported by the indexing pinssuch that the core may be shuttled by movement of the indexing pinassembly 12 to the right or to the left, as the case may be.

With the parts in the positions as shown in FIG. 2, the machine is soset up that upon being set in operation, the core 14 would be shuttledin successive increments of 12 cells each to the right. Assuming, forexample, that the welding wheel assembly has just returned from a sweepacross the ribbon section disposed above the pins 19 and 21 such thatthis ribbon section has been welded to the core, the electrode pins 19are then withdrawn from the core, or may have been withdrawn from thecore upon the return sweep movement of the welding wheel assembly 10. Onremoval of the electrode pins 19 from the core, the same is supported bythe indexing pins 21 and may be shuttled to the right as a unit with theindexing pin assembly 12. On shuttling the core, an additional length orsection of ribbon is withdrawn from the feed control device 16 andassumes a position of alignment with the confronting nodes of thecorresponding section of the upper ribbon of the core. The

electrode pins are then reinserted into the core beneath the lastmentioned ribbon section, following which the indexing pins arewithdrawn axially from the core and the assembly 12 returned to the areaof the welding station. The indexing pins are then inserted beneath thenewly superimposed section of ribbon 15 which is to be welded to thecore in the next cycle of operation of the welding machine.

When the core has been shuttled completely to the right such that thelast core section of increment of cells at the extreme left end of thecore have been formed at the welding station, both sets of electrode andindexing pins 19 and 21 are withdrawn axially from the core and the coreis lowered by one-half cell width following which the pins are againinserted into the confronting cells of the core. The wine glass controldevice 16 is then moved from the position shown to the right side ofpins 19 and 21 into a position comparable to that disclosed on the leftside of the pins, that is to say, device 16 will be similarly supportedon stripper bars 23 and 24 between which the core 14 builds up layer bylayer as the same is lowered one-half cell width at a time from the pins19 and 21. The base 25 of device 16 carries a pair of spaced dowel pins26 which are adapted to be received in openings 27 in stripper bar 23 toassure proper positioning of the device 16 on the stripper bars oneither side of the pins 19 and 21.

As the device 16 is moved to the right side of the pin assemblies, anadditional length of the ribbon 15 is withdrawn therefrom and doubledback over that portion which has just previously been welded to thecore, and this new section of ribbon falls naturally into alignmenttherewith, node for node, as aforedcscribed. The machine is then inposition for shuttling of the core by increments to the left to add thenext layer of cells to the core. When this layer has been completed, theextreme right end section of the core is positioned at the weldingstation and the core is again lowered one-half cell width and feedcontrol device 16 returned to the left side of the pins 19 and 21, asshown, to thus complete an overall cycle of operations of the machine.

This overall cycle thus, by way of review, includes a shuttling of thecore in one direction over the length thereof to complete one row ofcells of the core followed by shuttling of the core in the reversedirection and over the length thereof to form a second row of cells ofthe core. The core so fabricated, may be made to any desired length andmay be built up row-by-row to any width within the space limitations ofthe environmental surroundings of the machine. When desired, moreover,the machine may be shuttled continuously in either direction and thecore returned upon itself to form an endless belt.

Referring now more particularly to FIG. 1, it may be seen that thecorrugated ribbon 15 has flattened troughs 28 and crests 29 which formaligned and abutting nodes 28, 29 of adjacently disposed and oppositelycorrugated ribbon sections. As otherwise expressed, these adjacent andoppositely corrugated ribbon section are displaced relative to eachother by one half the spacing between corrugations, or by one half thelength of a cell as measured longitudinally of the core, with the resultthat the crests of one section are aligned and abutted with the troughsof the other. Upon welding together of these abutting nodes, generallydiamond-shape cells of square configuration are formed, but for theflattened crests and troughs which tend to give the cells a hexagonalconfiguration.

The aligned and abutting nodes 28, 29 to be welded are juxtaposed andsupported on the electrode pins 19 whose upper surfaces areappropriately matched to conform with the under surfaces of the crests29. The upper surfaces of the adjoining troughs 28 are electricallyengaged by the welding wheels 30 whose peripheral rim portions providean engaging surface area 31 whose width may be of the order of A thenodal width. Thus, in a specific case, the wheel rim perimeter 31 may be.010 inch wide and the nodal width approximately 0.04 inch. This allowsfor limited wandering or deviation of the wheels 30 from the intendedwelding swath to be laid down thereby when the welding current passesbetween the wheels and electrodes as the wheels sweep along the alignedand abutting nodes and across the adjacent ribbon sections to be weldedtogether.

In order to hold the welding swath or track along the nodessubstantially within the allotted dimensional width, the wheels must beprecision formed and rotatively mounted, and the alignment of theabutting nodes likewise must be precisely arranged. This, in turn,requires that the spacing between pins, both indexing and electrode, beaccurately established and maintained repetitively in the course of theseveral pin and wheel movements which must take place with each cycle ofoperation of the machine.

The electrode pins, as aforenoted, serve to align the crests 29, but itis one of the functions of the internesting indexing pins to assure thatthe abutting troughs 28 are properly aligned and juxtaposed therewithand this, in turn, assures that subsequently, the electrode pins will beproperly received into the cells previously formed about the indexingpins.

The core so formed from cell to cell and layer to layer comprises anintegral length, or spliced continuous length of ribbon which, asaforedescribed, is doubled back upon itself at each end of the core asindicated at 32,

as each new layer of cells is to be added to the core. When so doubledback over the indexing pins 21, as shown in internesting relation withrespect to the electrode pins 19 in FIG. 1, the precision forming of thecorrugations in the ribbon 15 and the precision forming and spacing ofthe internesting pins combine to assure that the abutting nodes willjuxtapose and align relative to each other and with respect to theelectrode pins. The end result is high quality core of uniform andconsistent cellular configuration and of virtually limitless length andbreadth.

The uniformity and consistency of the welds also contribute to thequality and strength of the core and this, again, depends on the extentto which the internesting pins effect the desired alignment, abutmentand general juxtaposition of the nodes with respect to the electrodepins. The tracking and pressure of the welding wheels are furtherfactors contributing to the achievement of satisfactory welds, as arethe parameters of the welding circuit and system as hereinafter morefully described.

It suifices to state with reference to FIG. 1 that the electrode pins 19are formed of highly conductive material and precisely spaced andembedded in plastic insulation in the head 20, these pins thereforebeing insulated from each other. Each pin 19 is separately brought outand connected to a transformer secondary winding 33, the other terminalof which is connected to the support 36 for the coacting electrode wheel30, as indicated schematically in FIG. 1. The indexing pins aresimilarly embedded in head 22 and thus precision spaced and electricallyinsulated but need not be so insulated or formed of highly conductingmaterial since they have no electrical function, the indexing pinspreferably being formed of cold rolled steel.

Each electrode pin 19 and its associated coacting electrode wheel 30 arethus connected in circuits individual thereto in series with a secondarytransformer winding 33. In the specific disclosure of 12 welding wheelsand 12 electrode pins there preferably are employed 4 transformers suchas the transformer 34 disclosed which has a primary winding 35 and 3secondary windings 33. By reason of this arrangement, the welds laiddown by each wheel are rendered independent of any circuit variationssuch as may be experienced by the circuits individual to the otherwheels. In prior art arrangements wherein the wheels may be connected inseries or in parallel arrangements, variations in the node contactpressures or wheel contact pressures produce variations in theresistance of the welding current paths with the result that anunfavorable weld condition experienced by one of the number of seriesconnected wheels may lessen the welding current and prevent satisfactorywelds by the others or, in the case of parallel connected wheels, thewelding current due to a burning through or shorting of one of thewheels may reduce the current to others below that required forsatisfactory welds.

Referring now more particularly to FIGS. 6 to 10, it will be seen thatthe electrode pins 19 and indexing pins 21 are formed and shapedidentically. As best seen in FIG. 10, the pins are formed from squarestock, the upper corner of which is removed to provide a top surfacewhich precisely fits the under surface of a node 29 (FIG. 1), of thecorrugated ribbon 15. Similarly, the upper diagonally directed surfaces91 precisely fit the di agonally directed undersides of the ribbonadjacent the node 29. Surfaces 91, however, are undercut as at 92 toprovide longitudinal grooves for receiving protrusions in the ribbonwhen the same is perforated, as at the time of forming the corrugationsin the ribbon. The lower corner of the square stock is removed to agreater extent than in the case of the upper corner with the result thatthe lower surface 93 is wider than the upper surface 90, and clearancegrooves 94, similarly formed in the lower diagonal surfaces 95,terminate in the surface 93. The rernaining portions of surfaces 95precisely fit the adjacent cell walls to thus assure precise forming ofthe cells but the material removed in forming bottom surface 93 andgrooves 94 provides clearance between the pin and the lower walls of theassociated cell. This clearance not only assures freedom of movement ofthe pins within the cells, and particularly with respect to perforationprotrusions which are directed alternately upwardly and downwardly asthe ribbon is doubled back and forth upon itself, but the clearance alsopermits use of ribbon which may be varied in thickness, as required, toprovide various strength patterns in the fabricated core.

A ribbon stop 96 is undercut to fit the upper surface of the pins asdisclosed in FIG. 10, one of these stops being used for each indexingpin 21 to which it is secured as by rivets 97. As may best be seen inFIG. 9, ribbon stops 96 are so positioned on the indexing pins such thatone end of a stop extends into the potting resin 22a which fills therecess 98 in the header member 22 for holding the indexing pins 21. Theribbon stops have suificient length along the indexing pins such thatthe opposite ends of the stops lie flush with the inner face of stripperbar 24, as indicated by the dashed line in FIG. 6. As will appear morefully as the description proceeds, an adjustment of the support framefor the indexing pins is provided to assure that the ribbon stops arethus properly aligned with stripper bar 24.

Each of the electrode and indexing pins is reduced in diameter as at 99.This has no utility in the case of the indexing pins, but in the case ofthe electrode pins, serves to receive a ferrule 100 which, in turn, hasa conductor cable N1 secured thereto. Ferrule will is secured, as bybrazing, to the electrode pin, and a suitable tube of insulation 102preferably covers conductor 101 and extends over the exposed end of theferrule. Potting plastic Zlla for retaining the electrode pins fillsrecess 98 in the header member 20 for holding electrode pins 19 and hasa rearwardly extending portion 2.6)!) which serves to insulate andsupport the cable ferrules fill).

Each of the electrode and indexing pins is tapered to a point 103 inorder to assure free entry of the pins into the cells of the core, andthe tips of the electrode pins are chrome plated, as indicated at 104 toavoid premature wear of the soft copper pins as the same move againstthe knife edge thin edges of the relatively hard stainless steelribbons.

As may be seen in the drawings, the electrode and indexing pin holders2i) and 22 per so are identical and each has spaced openings 105 toreceive suitable bolts, screws, or like fasteners, such as fasteners 106(FIG. to secure the holders to their respective supports 63 and 59respectively.

The internesting electrode and indexing pins 19 and 21, when insertedwithin the cells of the core, lie over the spaced stripper bars 23 and24 and bridge the same, as best seen in FIG. 6. The bars 23 and 24 arenotched as indicated at 107 (FIGS. 5 and 6) to receive the electrodepins and support the same in mutually spaced relation. Although hteelectrode fingers thus contact the steel stripper bars, the lowresistance of the fingers constitutes a preferential path for thewelding current through the fingers. The indexing pins 21 lie above theelectrode pins in internesting relation therewith, but lie above thestripper bars and clear the same to thus permit the indexing fingers toshuttle longitudinally of the bars. Thus, the core, which occupies thespace between the dashed lines (FIG. 6), is freely shuttledlongitudinally of the bars by the indexing fingers disposed within thecells of the core, the electrode pins, of course, being withdrawn fromthe core at the time of the shuttling movement.

Referring now more particularly to FIGS. to 18, it will be seen thateach of the wheels 30 is rotatively mounted on a pivoted member 36which, in turn, is pivotally connected as by the countersunk screw 37 toa vertically disposed member 38 to which the transformer lead may beconnected. The wheels 30 and their supports 36, however, are formed ofhighly conductive metal such as cop per whereas the member 38 preferablyis formed of the less conductive steel. It is preferred therefore thatthe transformer lead or cable 108 be secured, as by brazing, directly tothe copper member 36 which, for this purpose, has a terminal portion 109to which the cable is connected.

Each wheel 30 is secured to its support member 36 by means of acountersunk screw 11%, which in the manner of mounting of screw 37, hasa countersunk opening 111 provided therefor in member 36. The wheel hasa large central opening 12 which receives the shoulder or hub 113 of asteel washer-shaped nut 114 upon which the wheel is journalled forrotation. The inner face 115 of nut 114 is recessed at 116 which thusreduces the area of the bearing surface afforded by face 115 in slidingengagement with the hub face 117 of the wheel. The diameter of bearingface 115, however, is significantly large and serves to prevent wobbleof the wheel on the hub bearing surface 113 when the opposite hubsurface 118 of the wheel is moved against the inner surface 119 ofmember 36, as by tightening screw 110 into the threaded opening 120provided therefor in nut 114. Face 119 is also recessed as at 1221 toreduce the bearing area of the wheel on face 119, particularly in viewof these surfaces both being copper. The area of contact or electricalengagement of surfaces 118 and 119 is ample, however, to optimu-mly passthe welding current between the wheel and support member 36, and theanti-wobble bearing arrangement assures electrical circuit continuitybetween these parts.

As may best be seen in FIGS. 17 and 18, the lower end 122 of member 38is reduced in thickness and is shaped similarly to the hub portion ofwheel 30, having a central opening 123 for receiving the hub 113 of anut 114, and having opposite faces 124 and 125 for respectively engagingfaces 115 of nut 114 and face 119 of member 36. A recess 1Z6, concentricwith the axis of hub 113 and screw 37, is provided to reduce the bearingarea of face 119 of member 36 in engagement with face 125 portion 122 ofmember 33, and the reduced face 115 of nut 114 similarly provides alimited bearing area in engagement with face 124 of :member 38. Screw37, as in the case of screw 110, engages its associated nut 114 to movethese bearing surfaces into face adjacency.

Referring now more particularly to FIGS. 15 and 17, each member 38carries a threaded pin 41 which is threaded therein and locked theretoby a nut 127. Pin 41 terminates in a bifurcated member 128 which, inturn, carrie's an adjustment screw 129 against which a compressionspring assembly 42 is urged, the other end of this assembly being urgedagainst wheel pivot member 36 with the result that wheel 30 is urged byits spring assembly to move in a downwardly direction.

This downward movement of the wheel is limited and adjustable by asecond threaded pin 130 which is threadedly received in member 38,locked thereon as by a nut 127, and passed therethrough to engage a stop131 in the form of an angularly bent upstanding portion of member 36.

A second angularly bent upstanding portion 132 of member 36 has a recess133 formed therein which serves to seat the tip of the tapered pin 134.Pin 134 is enlarged as at 135 and 136 to provide a seat for compressionspring 137 of the spring assembly 42. The other end of spring 137 issimilarly seated on shoulders 138 and 139 formed on a tapered pin 146which seats in the cupped end of adjustment screw 129. The shank 141 ofpin is drilled out as at 142 to slidably receive the shank of pin 134therewithin to thus make provision for pivotal movement of member 36about the axis of screw 37 while retaining the spring assembly 42 incompressive engagement with screw 129 and seat 133.

Adjustment of stop screw 130, as aforedescribed, limits the downwardpivotal movement of wheel 30 and its support 32, and adjustment of screw12? determines the extent of initial compression of spring 137 in urgingthe member against the stop screw 130. The contact pressure with whicheach wheel 30 engages the ribbon nodes to be welded as the wheel movesyieldably thereagainst may thus be accurated predetermined and preset,working directly with the wheel sub-assembly unit as disclosed in FIG.15.

Elongated clearance openings 143 are provided in each member 38 toreceive suitable fasteners 144 (FIGS. 11 to 14) for securing the same toan adapter plate 145 and intermediate sheet 40 of insulation materialsuch as micarta. The heads of screws 144 actually engage retainer pieces146 having insulation pieces 147 which, in turn, engage members 33 andbridge the elongated openings 143 therein. Screws 144 which clear theopenings 143 may thus be tightened to clamp members 38 together as aunit in adjusted positions on adapter plate 145 without connecting thesame electrically together through the adapter plate.

It will. be understood that the wheel sub-assemblies will be made indifferent sizes in accordance with the various cell sizes of honeycombcore to be fabricated and, accordingly, the parts may be smaller, notethe reduced thickness of parts 38 in FIG. 13 as compared to the sameparts as in FIG. 14, and the wheel sub-assemblies may be closely orwidely spaced on the adapter plate. In FIG. 13, for example, a largenumber of thin, closely spaced wheel assemblies, spaced in accordancewith the spacing between cells of the core to be fabricated, areemployed in an arrangement in which welding is to occur in only onedirection of sweep of the wheels over the abutting ribbon nodes. In FIG.14, by way of contrast, the parts are larger and the spacing between thewheel subassemblies is greater, the arrangement being one in whichwelding is to occur on both passes of the wheels back and forth acrossthe abutting ribbon nodes, the wheels, however, being shifted laterallyby one cell width, after passing across alternately spaced nodes, inorder to weld the intermediate nodes on the return stroke of the wheels.

The adapter plate 145 is secured as by four screws 148 to a movablesupport member 39 (FIG. 19) which, for this purpose, has four threadedopenings 149. Member 39 is mounted on a fixed head member 44 for raisingand lowering movements, and also for side to side movements, of thewelding wheels with respect thereto, these movements being accomplishedby means of an interfitting centrally disposed member 1511. To this end,member 39 has rearwardly extending upper and lower ears 151 and 152,respectively, which ears have longitudinally extending openings 153 forreceiving pins 154-, in turn, receivable in apertures formed therefor inupstanding and depending ears 155 and 156, respectively, on member 1511.In assembling members 3& and 156, the same are first moved together withpins 154 being removed. Once assembled, the pins are inserted thru theopenings 153 and inserted as with a press fit within the openings inears 155 and 156, or by threaded engagement therewith.

The upper and lower surfaces of member 150 similarly carry upstandingand depending pins 43 which are secured thereto after first being passedthrough openings 158 provided therefor in forwardly extending ears 159and 160 on member 44. This is done, of course, when members 4-4 and 151)have first been fit together such that their pin receiving openings arealigned.

When members 39, 1511 and 44 have been assembled, as aforedescribed,member 39 and the wheel sub-assemblies supported thereon may be shiftedlaterally and slidably along pins 154 and relative to members 150 and 44which are constrained to vertical movement relative to each otherslidably along pins 43. This lateral movement is effected as an incidentof the movement of the members 39, 150 and 44 as a unit, namely, weldinghead 10, as the same moves to forward and return end limit positionsaxially of the unit support rods 71) and 71 which are suitably securedto fixed member 44 and bosses 161 thereon, as by fasteners 162 (FIG.ll). Members 39 and 150 have openings 163 and 164 for freely receivingthese bosses, as best appears in FIGS. 11 and 19.

To effect the lateral shift, member 39 carries an upstanding pin 165which is adapted to be received in the bifurcated end 166 of a bellcrank 167 which is pivotally mounted on member 44- by means of a pin168. The other end of the bell crank has an opening to receive theupturned end of a long rod 169, the same being secured therewithin by acotter pin 17%). Rod 169 also freely passes through an apertured bracket171 which is suitably secured as at 157 to frame member 68.

Collars 172 and 173 are secured to rod 169 fore and aft of bracket 171and spaced with respect thereto such that, as the welding head 10 andwelding carriage frame, generally designated W, move forward, rearcollar 1'73 is utilimately stopped by bracket 171, and this causes bellcrank 167 to be pivoted counter clockwise about pin 168 as the forwardmovement is completed thereby causing member 39 and the wheelsub-assemblies supported thereon to be shifted to the right as viewed inFIG. 19.

On the return trip, collar 172 is stopped by the bracket, the bell crankpivots clockwise, and the shift of member 39 and the wheels is then tothe left, thereby completing the shifting cycle.

An offset leaf spring 174 suitably secured to member 44 as at 175engages the rod-coupled end of bell crank 167 such that it moves with asnap action into the two shift positions provided, these beingdetermined and set precisely by adjusting screws 176 (one only beingshown) which are provided at each end of member 39. These screws extendthru ears 152 for engagement, respectively, by the ears 156 of member150.

When the lateral shift of the wheels is not required, as when thewelding is accomplished entirely on the forward pass of the wheels, thecollars 172 and 173 are simply spaced a greater distance from bracket1'71 such that bell crank 167 is not activated by movement of weldingcarriage W.

Member 1511 has a bifurcated bracket 80a secured thereto (FIG. 19) as bysuitable fasteners 175 and provides a pair of spaced upstanding lugshaving aligned openings 177 for receiving a pivot pin 80 (FIG. 2). Bythis means wheels 31), their adapter plate 145 and members 39 and 150may thus be lowered relative to the fixed plate 44 to bring the wheelsinto engagement with the abutting 12 nodes, and further loweringmovement of the member 39 after the wheel engagement is thusestablished, causes predetermined compression of the spring assembly 4-2to thus provide a required contact pressure of the wheels on theassociated nodes.

The success of the welding operations and the quality of the fabricatedcore depend in large measure upon the precision with which the weldinghead 10 and the electrode pin and indexing pin assemblies 11 and 12 maybe moved repetitively to engage the ribbon and core and to shuttle thecore following the welding of each series of aligned and abutting nodes.The precision with which these movements may be executed depends, inpart, on the motor drive system hereinafter generally disclosed andwhich constitutes the claimed subject matter of a copending applicationfor Drive System for Honeycomb Core Machine, Serial Number 207,162,filed June 29, 1962, now Patent No. 3,163,742, dated December 29, 1964,to which reference may be had for further details of operation andconstruction. The precision of these movements also depends upon theframework support for the assemblies 1t 11 and 12. This framework 13comprises a main frame and several subframes presently to be described,as may best be seen by reference to FIGS. 2 to 4.

The main frame comprises two basic structural members in the form of apair of spaced parallel tubes 45 and 46 the inherent rigidity andtorsional strength of which provides basic support for the otherstructural members of the machine, and by reason of the telescopicnature of the tubes serves to slidably support the subframe designated Iupon which the indexing fingers 21 are mounted for axial movement, aswill presently appear. The structure for supporting the tubes 45 and 46with respect to a support surface such as a table top or floor surfacemay comprise a base member 8 and one or more uprights 51 (FIG. 4) whichsupport the transformers 34. The uprights support a pair of U members 47the spaced legs of which provide space support for the tubes, therebeing one such U member for each of the tubes. The extremity of each legof U member 47 is apertured to receive its engaging tube and each leg issevered along a diameter of the tube as indicated at 48 to providecomplementary gripping surfaces to clamp the leg to the tube, thesevered extremity 49, for this purpose, being secured to the main legportion as by suitable threaded fasteners 50. This manner of clampingvarious structural members to the tubes and to like members of circularcross section is employed throughout the several parts of the frameworkand, accordingly, this clamping feature will not again be described indetail.

Slidably supported within tubes 45 and 46 are a pair of elongated rods52 and 53, respectively, which extend beyond either end of the tubes. Atthe rear end of the tubes, rods 52 and 53 are interconnected by a crossmember 54 which has openings for receiving the rods interfittinglytherewith and has substantial width axially of the rods so as to effecta rigid rectangular subframe therewith, hereinbefore generallydesignated 1. This rigid rectangular subframe is completed at theforward extended ends of rods 52 and 53 by a second rigid rectangularframe designated S and comprising a pair of depending members 55 and 56which are respectively clamped to the ends of rods 52 and 53. Thesedepending members, in turn, are rigidly interconnected as by fasteners178 to a pair of spaced parallel rods 57 and 58, FIG. 5.

Slidably supported on rods 57 and 58 is an inverted U member 59 whoselegs are suitably apertured to slidably receive the rods. The base ofslide 59 is suitably formed to provide for interfitting engagement withindexing pin head 22 to which it is preferably secured detachably, asaforedescribed (FIG. 5). The spacing between tubes 45 and 46 and rods 52and 53 is such that slide member 59 and the indexing pins and headsupported thereon may be moved fully to either side of the electrodepins when the same have been withdrawn axially from the indexing pins,

thereby to shuttle the core 14 by an increment of 12 newly formed cellsof the core. This shuttling space to the left of the machine, with theparts in position as shown in FIG. 2, is occupied by the ribbon feedcontrol device 16 and, accordingly, the shuttling of the core, as shown,occurs to the right of the machine. When the indexing head 12 has beenmoved into this shuttling space on the right of the machine, thesubframes 1 and S are readily moved as a unit forwardly of the machineby reason of the free sliding movement of the rods 52 and 53 in thespaced parallel tubes 45 and 56. This movement of these subframes causesaxial withdrawal of the indexing pins 21 from the core, and the indexinghead and its slide support 59 may then be slidably moved along rods 57and 58 to restore the indexing head to the welding station at which timethe subframes I and S may be moved as a unit rearwardly of the machinefor re-engagement of the indexing pins with the core and internestingengagement with the electrode pins 19.

Each of the stripper bars 23 and 24 at each end thereof, has securedthereto and extended upwardly therefrom a member 60, the upper end ofwhich is formed as heretofore described for clamping engagement with theassociated tubes 45 and 46, as the case may be. This clampingarrangement readily permits of adjustment of the stripper bars 23 and 24axially of the tubes 45 and 46 to thus accommodate between the stripperbars variable core thicknesses within limits imposed by the overlappinglength of the indexing and electrode pins. It will be understood,moreover, that indexing and electrode heads 11 and 12 having differentfinger lengths may be installed on the machine to thus provide forvariable core thicknesses, as measured in terms of the width dimensionof the ribbon 15, of the order of upwards of inches.

Referring now particularly to FIG. 4, it will be seen that a pair ofmembers 179 and 134 secured respectively at both sides of the machine tothe ends of stripper bars 23 and 24, and to their associated supportmembers 60, have angularly bent portions 181 and 132 which serve tosupport a pair of elongated longitudinally extending bars 183 and 184.These bars, like stripper bars 23 and 24, define a vertical channelthrough which the fabricated core builds up row by row of the cells ofthe core.

Members 185 and 186 are secured respectively to bars 183 and 184 anddepend therefrom and terminate in longitudinally extending bars 187 and188. A core support 189, such as a block of plywood, is disposed beneaththe core 14 during fabrication of the first several rows of cells and isperforated in simulation of the spacing between cells to receive pins190 which bridge the bars 187 and 188 and slide therealong as the coreis shuttled from side to side. When the core has been built upsutficiently to clear the bars 183 and 184, the same may be used tosupport the pins 190, the board or support 189 then being removed fromthe machine. Pins 190 in any event provide support for the core as thesame extends beyond the ends of stripper bars 23 and 24 to either sideof the machine, and provide the entire support for the core as when bothelectrode and indexing pins 19 and 21 are withdrawn therefrom.

Support 189 alternatively may be fabricated from a light weight metalmember of T cross section to which spaced sheet members 191 are secured,substantially as shown.

In the manner heretofore described for the indexing pin subframe I,there is provided a similar subframe designated E for the electrode pins19. Subframe E thus similarly comprises a pair of spaced rods 61 and 62which, at their forward ends, are interconnected by a cross member 63 towhich they are rigidly secured in any suitable manner. Cross member 63serves to support the electrode pin head 20 to which it is securedpreferably cletachably by suitable fastener means (not shown) bututilizing mounting holes 105 in holder 21], as aforedescribed. The otherend of rods 61 and 62 are interconnected by a cross member 64 to whichthey are rigidly secured, cross member 64 being generally similar, andits manner of attachment to rods 61 and 62 being generally similar tothe construction and arrangement heretofore described in connection withcross member 54 of subframe I.

Subframe E is mounted for free sliding movement and axial movement ofthe electrode pins 19 parallel to the axes of tubes and 46 by means of apair of spaced parallel cross members 65 and 66 which interconnect thetubes and are clamped at the ends thereof to the tubes, the clampingarrangement being as heretofore described in connection with main framesupport member 47. Rods 61 and 62 are mounted for free sliding supportin openings suitably provided therefor in cross members 65 and 66, theseopenings being aligned such that the rods in their sliding movementsmove parallel to the axes of tubes 45 and 46.

Cross members 65 and 66 are generally C-shaped and generally depend fromthe spaced tubes 45 and 46. Cross member 65, however, in that centralportion 67 thereof extending between spaced parallel rods 61 and 62 isdirected upwardly to provide a clearance space for electrical cables 101and 108 which individually connect to and terminate at the electrodepins 19 and wheel subassemblies respectively. A support 67a for thesecables conveniently is secured, as shown (FIGS. 3 and 4) to upstandingportions of cross member 65.

An additional pair of generally C-shaped spaced parallel cross members68 and 69 interconnect tubes 45 and 46 and are clamped thereto asheretofore described. These C-shaped cross members are directed upwardlyrelative to the tubes and provide the sliding support for the weldingrectangular subframe W which, in a manner similar to the othersubframes, comprises a pair of spaced parallel rods 70 and 71 which aremounted for sliding movement parallel to the axes of the tubes 45 and46. The rear end of rods 70 and 71 are interconnected by a cross member73 to which they are rigidly secured, and the forward ends of these rodshave the fixed welding head member 44 secured thereto, asaforedescribed. By reason of this sliding movement for welding subframeW, the same is constrained to move parallel to the axes of tubes 45 and46 to thus assure that the wheels 39 are directed with precision alongand parallel to the aligned and abutting nodes juxtaposed upon theelectrode pins 19.

Welding subframe W provides support for a longitudinally extended member74 which is secured in elevated position above this subframe by means offore and aft members 75 and 76 which are secured respectively to headmember 44 and cross member 73, this superstructure being removed in FIG.3, and being disclosed in part in FIG. 11 wherein member 75 is disclosedas being secured to member 44 as by suitable fasteners 75a. A pair ofvertically disposed members 77 depend from either side of member 74 towhich they are secured and provide as at 78 a pivot support for a lever79, the front end of which is pivotally secured as at 80 to thevertically movable portion 39 of the welding head, aforedescribed. Theother end of lever head 79 has secured thereto on either side thereof apair of vertically disposed depending members 81 which provide a pivotalsupport as at 82 for a cam follower wheel 83. Wheel 83 is mounted incooperative relation to a cam 54 having rise and fall surfaces 85 and 86which are spaced in accordance with the width of ribbon 15. Cam 84 issupported on cross members 68 and 69 to which it is suitably extendedand interconnected, as may best be seen in FIG. 3. By reason of thisarrangement, sliding movement of the welding subframe W to sweep thewheels across the ribbon also causes, by reason of the coaction betweenwheel follower 83 and cam 84, a downward movement of the verticallymovable cam head portion 39 with the result that the wheels 30 firstengage the aligned ribbon nodes and thereafter build up a desiredcontact pressure therewith as the spring assemblies 42 are compressed byfurther lowering movement of head member 39.

In the arrangement of the parts as disclosed in FIG. 4, the machine isset for welding only in the forward pass of wheels 30 over the core. Toacomplish this, members 81 are mounted for pivotal movement about a pin193 carried by lever 79, being yieldably biased to the upright positionshown by a spring 192 which interconnects members 81 and member 74. Apin 194 carried by members 81 engages lever 79 to prevent counterclockwise movement of the members about pivot 193 when wheel 83 engagescam surface 85. Hence the wheel assembly is lowered as carriage Wadvances to move the welding head across the core. A coil spring 195interconnecting lever 79 and member 74 raises the welding head as wheel83 moves down the cam surface 86 at the end of the forward stroke. Asthe wheel engages cam surface 86 on the return stroke, members 81 arenow free to move clockwise about pivot 193 as spring 192 is therebytensioned. As a result, the welding head is not lowered on the returnstroke.

When welding is desired on both the forward and return strokes of thewelding head 10, members 81 are fixed to lever 79, this beingaccomplished by removing pin 194 and rotating members 81 counterclockwise until the same are aligned with lever 79 such that pin 194 maybe reinserted to pass through an opening 196 therein. Members 81 beingthen looked to lever 79, engagement of wheel follower 83 with both camsurfaces 85 and 86 will cause lever 79 to tilt and thus lower thewelding wheels.

It will be understood that additional cams like cam 84 which aresimilarly mounted cooperate as with a cam follower switch 197 which mayserve to switch the welding current on and off as the wheelsrespectively engage and leave the abutting nodes. Similarly a second camhaving several peaks may similarly be engaged by another cam followerswitch to cause tack welding of the abutting nodes at spaced intervalstherealong. Still another switch and cam arrangement may be similarlyemployed to direct cooling air to the wheels 30 during the passage ofthe welding current and to direct the air against the unwelded ribbonthereby to urge the same against the electrode pins preparatory towelding.

An arrangement for so directing the air is disclosed in FIGS. 11 and 12wherein it may be seen that air from a source, not shown, is supplied byway of a flexible tube 198 to the inlet 198a to an air manifold in theform of a rigid tube 199. Depending from manifold tube 199 in spacedrelation therealong is a plurality of air outlet tubes 200 from whichthe air passes in jets and strikes the ribbon to urge the same againstthe electrode pins. The air on being reflected from the ribbon strikesthe wheels to cool the same, and to this end, the air is turned onbefore the welding wheels engage the ribbon and before the weldingcurrent is caused to flow.

Manifold tube 199 is secured at each end to an arm 261 which extendsrearwardly and then upwardly to be secured as by a suitable fastener 202to member 39, fasteners 292 being received in openings 203 on oppositesides of member 39. A pin 204 on one arm 201 mounts a coil spring 205which is anchored on the other end thereof as on leaf spring 174. A lug206 on this arm carries a stop screw 207 which engages adapter plate 145to limit movement of air outlet tubes 200 toward the wheels undertension of spring 205.

The ease of the free sliding movement of subframes l, S, E, and W isgreatly facilitated by the use of linear bearings 72 which are employedwithin tubes 45 and 46, on shuttle slide member 59, and on cross members65, 66, 68, and 69. Such linear bearings are well known and may be ofany type suitable for the purposes such, for example, as thosemanufactured and sold by the Thompson Ball Bushing Company whoseXA122026 linear bearings are particularly well suited for the purpose.

Referring now to FIGS. 3 and 4, it will be seen that a first pair ofspaced rods 29-3 extend rearwardly from cross frame member 69 to whichthey are secured, each by a fastener block 2tl9. A second pair of rods210, disposed below rods 208, extend rearwardly from cross frame member56 to which they are suitably secured. These rods are securedrespectively to upper and lower plates 211 and 212 having bent andapertured portions to receive the same whereby the plates are secured tothe threaded ends of the rods as by the nuts 213.

Extending between plates 211 and 212 and suitably secured thereto as bywelding is an angle member 214. Three extensions or lugs 215 from thefore-to-aft leg of angle 214 serve as stops for carriage frames W, I andE, these respectively appearing from top to bottom in FIG. 4. Upper stoplug 215 coacts with a stop pin 216 adjustably threaded to cross beam 73and secured thereto by lock nut 217, to thus limit the rearward movementof welding frame W. A similar stop pin 21$, similarly adjustably securedto the forward side of beam 73, limits the forward movement of weldingcarriage W as pin 218 moves to engage fixed cross beam 69.

Similarly, cross beam 64 of the electrode pin frame E carries stop pins219 and 229 fore and aft of the beam which respectively engage beam 66and bottom stop 215 as the electrode supporting frame E moves fore andaft to insert and withdraw the electrode pins 19 from the cells of thecore.

In the same manner, cross beam 54 of the supporting frame I for theindexing pins carries stop pins 221 and 222 fore and aft of the beam,these pins respectively engaging a plate 69a (FIG. 4) whichinterconnects cross beams 66 and 69 and intermediate stop 215, to thuslimit the fore and aft movements of frame I as the indexing pins areWithdrawn from the core and reinserted therein, respectively. Asaforementioned, ribbon stops 96 on indexing pins are aligned at theextended ends thereof with the inner face of stripper bar 24 and this isaccomplished through adjustment of stop pin 222 on cross beam 54.

Referring again to FIG. 5, it will be seen that shuttle member 59 islimited in its movements on rods 57 and 58 by fixed set screws 223 whichare secured respectively to members 55 and 56. In addition, a pair offloating stop pins 224 and 225 are provided for the right and left sidesof the machine, each having a crank arm 226 which terminates in a ball227. Pins 224 and 225 are mounted for sliding movement in tubes 229 and230, respectively, which are secured as by welding to their associatedmembers 55 and 56, these members having aligned openings through whichthe pins extend.

Each of tubes 229 and 230 are slotted longitudinally as at 231, andthese slots terminate in a lateral slot 232, in order to accommodatemovements of arms 226. Thus, arm 226 for pin 224, to reach the positionshown in FIG. 5, would be moved to the left along slot 231, beingextended at this time horizontally from tube 225 until slot 232 isreached. Arm 226 and ball 227 are then moved downward to the positionshown to thus lock pin 224 in a position to limit movement of member 59completely to the right. The shuttling movement of member 59 is thenrestricted to engagement with pin 224 in movements to the right andengagement with stop pin 223: in movements to the left.

When the shuttling direction of the core is to be reversed, arm 226 forpin 224 is raised and moved to the right along slot 231, the pin thenhaving a position as depicted for pin 225 in FIG. 5. With shuttlingmember 59 then positioned either in its center position or to theextreme right in contact with stop pin 223, pin 225 is moved to theright until its arm can be lowered into slot 232. This then places pin225 into a position comparable to that depicted for pin 224 in FIG. 5,and this will then restrict further shuttling movement of member 59 tomovements between pin 223 on the right and pin 225 on the left. The fineadjustments afforded by the set screws 223 and the like arrangement onthe ends of pins 224 and 225 assures that member 59 and the indexingpins supported thereon will always be moved in exact incrementscorresponding to an integral multiple of the spacing between the cells.

Member 59 has mounted thereon, as by fasteners 233, a bracket 234 havingforwardly extending apertured arms for receiving a pair of bolts 235which are suitably secured thereto as by nuts, as shown. The ends ofbolts 235 carry cable clamps 236, or the like, to which opposite ends ofa single cable 237 are respectively secured in a well known manner. Thecable from one clamp 236 passes over a pulley 238 mounted on member 56,and then passes over a second pulley 239. The cable from the other clamp236 passes over a pulley 240 which, together with pulley 239, is mountedon a bracket 241, in turn, secured as by fasteners 242 to member 55.From pulleys 239 and 240, the cable is directed rearwardly over pulleys243, also pivotally supported on bracket 241, to a drum 244 (FIG. 3)about which it is wound in threaded grooves and to which it is suitablysecured.

Sheave or drum 244 is driven thru a gear box 245 by an electric motor246a, these elements together comprising a unit generally designated 246which may be of any type suitable for the purpose such, for example, asthe actuator manufactured by Lear, Inc. of Grand Rapids, Michigan.

The motor per se for such an actuator has a rated speed of the order of20,000 r.p.m. and therefore incorporates a magnetic clutch to disengagethe motor from the gear train in order to avoid over running due to theinertia of the motor armature. A brake is also incorporated which locksthe gear train to the gear housing as the motor is disengaged from thegear train. Similarly, the brake releases the gear train as the motor isenergized and establishes a driving connection with the gear trainthrough the magnetic clutch.

It is a feature of the cable drive for shuttle member 59, however, thatthe same be moved into position against its stops before the drive motoris deenergized. This is accomplished by mounting the actuator unit forrotation yieldably about the axis of cabled drum 244 and against theforce of a U-shaped torsion rod spring 247, one end of which is securedto the gear box housing as at 248 and the other end of which is securedto a mounting bracket 249, in turn, secured to cross beam 54 by bracket249a. By reason of this arrangement, when the member 59 moves againstone of its stops, further winding of the drum ceases as the cabletensions, and further rotation of the motor armature rotates the gearhousing which has a pin arranged to engage the actuating button of oneof two micro switches, now shown, depending on the direction of rotationof the gear case about the drum or actuator drive axis. A break-makeswitch combination in the micro switch thus actuated deenergizes themotor and the make portion of the switch combination serves as asequence switch for initiating a followup function of the machine.Another sequence switch connected in series with the break portion ofthe other micro switch, when closed in the cycle of operations of themachine, will energize the motor for operation in the reverse directionuntil the gear box rotates sufficiently in the opposite direction toactuate the other micro switch and again deenergize the motor, themember 59, however, having meanwhile been brought to a positive andprecise stop at its initial position.

As a safety precaution, drum 244 preferably is driven from the gear box245 through engaging clutch plates 250 and 251, plate 250 being securedto the output of the gear train and plate 251 being suitably secured todrum 244. These clutch plates are yieldably urged toward each other witha pressure determined by the compression of a laterally offset washertype spring 252 which is interposed between pressure plates 253 and 254.Plate 254 bears freely rotatively against the gear case coaxially withclutch plates 250 and 251 but is not connected to the gear train.Similarly, a bolt 255 passes freely through drum 244, clutch plates 250and 251, gear box 245, pressure plates 253 and 254, washer spring 252,and thence through a plate 256 comprising a portion of the mountingbracket. Bolt 255 serves, upon tightening of nuts 257 thereon, tocompress spring 252 between plates 253 and 254 to thus develop pressurebetween the engaging surfaces of clutch plates 250 and 251.

Motor actuator assemblies generally designated 258, 259 and 260, similarto the aforedescribed shuttle drive 246, for the indexing pins, areemployed respectively to drive the welding head and frame W, theelectrode pins and frame E, and the indexing pins and frame I.

Actuator assembly 258 is supported on cross beam 73 and its cable 261extends to and passes around a pair of pulleys 262 which direct oppositeends of the cable fore and aft of the beam for securing in the manneraforedescribed to plate 69a (FIG. 4) as at 263 and to angle 214 as at264. Pulleys 262 are supported on a bracket 265, in turn, secured to theunderside of beam 73.

Actuator assembly 259 is supported on cross beam 64 and its cable 266extends to and fore and aft from a pair of pulleys 267 supported in abracket 268, in turn, secured to beam 64, the fore end of cable 266being secured as at 269 to plate 69a and the aft end being secured as at270 to angle 214.

Actuator assembly 260 is supported on cross beam 54 and its cable 271extends to and fore and aft from a pair of pulleys 272 supported in abracket 273, in turn, secured to beam 54, the fore end of cable 271being secured as at 274 to plate 69a and the aft end thereof beingsecured as at 275 to angle 214.

From the foregoing, the operation of the core fabricating machine asherein disclosed should now be fully apparent and, likewise, thefeatures and functions of the welding, electrode, and indexing heads andof the framework and subframes in assuring the desired precision ofmovement of the welding head and electrode and indexing pin assembliesshould also be apparent to thus fulfill the aforesaid objects andfeatures of the invention. It will be apparent, for example, that themodular components of the machine are readily adapted for replacementand repair and that the mechanisms of the machine lie largely to therear of the ribbon and core being fabricated to thus place thefabrication process substantially in full view of and available forready access of an operator in attendance at the machine. The openskeletal framework, moreover, not only constitutes a light weightstructure, but presents the moving mechanisms and parts in fulloperative surveillance and for ready access in case of need for repairs.

While the invention here involved has been embodied in a singledisclosed perferred form, it will be apparent to those skilled in theart, to which the invention most closely relates or appertains, that thesame may be embodied in other forms or carried out in other ways without departing from the spirit or essential characteristics thereof. Thepresent embodiment of the invention is therefore to be considered as inall respects illustrative and not restrictive, the scope of theinvention being indicated by the appended claims, and all changes thatcome within the meaning and range of equivalency of the claims areintended to be embraced therein.

Having thus described our invention, what we claim is new and useful anddesire to secure by Letters Patent is:

1. In a welding system, a welding wheel of highly conductive material, arotative journal support for said wheel having a side anti-wobbleannular bearing surface concentric with the wheel axis and complementaryto and slidably engaged with a side surface thereof, said rotativesupport being formed of a bearing material complementary to that of thewheel, a fixed support having said rotative support secured thereto andhaving a side anti- Wobble annular bearing surface concentric with thewheel axis and complementary to and slidably engaged with the oppositeside surface of the wheel, sa d fixed support being formed of a highlyconductive material and said annular anti-Wobble surface thereof inslidable engagement with the complementary surface of the wheelcomprising a sliding electrical contact for passing welding currentbetween the wheel and the fixed support.

2. In a Welding system as in claim 1, said rotative support having ahub, said Wheel having a central aperture for receiving the hub as ajournal support therefor, and means for securing said hub to said fixedsupport.

3. In a welding system as in claim 2, said fixed support having acountersunk opening concentric with said annular anti-wobble surfacethereof, said hub having a central threaded opening, and said securingmeans comprising a screw threadedly received in said hub opening andhaving a tapered head seated in said countersunk opening in the fixedsupport.

4. In a welding system, a modular component comprising a Welding wheelof conductive material, a first wheel support of conductive material,complementary annular sliding electrical contact surfaces on confrontingside faces of said wheel and support for passing welding currenttherebetween, a rotative support of complementary bearing material forsaid wheel secured to said first support, complementary annular bearingsurfaces on confronting side faces of the wheel and said rotativesupport, a second wheel support extending substantially normally of andpivotally secured to said first support for limited pivotal movementabout an axis parallel to the wheel axis, adjustable stop means on saidfirst and second supports for limiting said pivotal movementtherebetween, and adjustable spring means interposed under compressionbetween said first and second supports for urging the same yieldablyagainst said stop means.

5. In a welding system as in claim 4-, said second support having acentral opening concentric with said pivot axis, a journal support forsaid second support having a hub disposed in said central opening andsecured to said first support, said first and second supports havingcomplementary annular anti-wobble bearing surfaces provided onconfronting faces thereof and disposed concentrically of said pivotaxis, said second support and said journal support therefor havingcomplementary annular anti-Wobble bearing surfaces provided onconfronting faces and disposed concentrically of said pivot axis.

No references cited.

ANTHONY BARTIS, Acting Primary Examiner.

RICHARD M. WOOD, Examiner.

R. F. STAUBLY, Assistant Examiner.

1. IN A WELDING SYSTEM, A WELDING WHEEL OF HIGHLY CONDUCTIVE MATERIAL, AROTATIVE JOURNAL SUPPORT FOR SAID WHEEL HAVING A SIDE ANTI-WOBBLEANNULAR BEARING SURFACE CONCENTRIC WITH THE WHEEL AXIS AND COMPLEMENTARYTO AND SLIDABLY ENGAGED WITH A SIDE SURFACE THEREOF, SAID ROTATIVESUPPORT BEING FORMED OF A BEARING MATERIAL COMPLEMENTARY TO THAT OF THEWHEEL, A FIXED SUPPORT HAVING SAID ROTATIVE SUPPORT SECURED THERETO ANDHAVING A SIDE ANTIWOBBLE ANNULAR BEARING SURFACE CONCENTRIC WITH THEWHEEL AXIS AND COMPLEMENTARY TO AND SLIDABLY ENGAGED WITH THE OPPOSITESIDE SURFACE OF THE WHEEL, SAID FIXED SUPPORT BEING FORMED OF A HIGHLYCONDUCTIVE MATERIAL AND SAID ANNULAR ANTI-WOBBLE SURFACE THEREOF INSLIDABLE ENGAGEMENT WITH THE COMPLEMENTARY SURFACE OF THE WHEELCOMPRISING A SLIDING ELECTRICAL CONTACT FOR PASSING WELDING CURRENTBETWEEN THE WHEEL AND THE FIXED SUPPORT.